CVE-2026-124952 - Use-after-free in the Audio/Video component

Q: What must an attacker do to exploit this issue?

The CVSS vector indicates the attack can be delivered over a network without attacker privileges, but it requires user interaction. Successful exploitation can affect confidentiality, integrity, and availability.

Q: How can I tell whether my Firefox ESR installation is affected?

Check the installed Firefox ESR version. The issue was fixed in Firefox ESR 115.45, so installations not updated to that fixed release should be remediated.

Affected Software

2 affected componentsFixes available

Mozilla Firefox ESR<115.45

115.45

Remediation

Recommended actions to resolve this vulnerability, in priority order.

Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 115.45
Upgrade
Upgrade Firefox ESR to a version that resolves this vulnerability.
Fixed in 115.45

Event History

Nov 10, 2026

CVE Published

via Mozilla·12:00 AM

Data Sourced

via Mozilla·12:00 AM

DescriptionSeverityAffected Software

CVE Published

via MITRE·01:29 PM

Data Sourced

via MITRE·01:29 PM

Description

Data Sourced

via NVD·02:17 PM

DescriptionSeverityWeakness

Parent advisories

This vulnerability appears in the following advisories.

MFSA2026-126

Peer vulnerabilities

Found alongside the following vulnerabilities.

Frequently Asked Questions

1

What must an attacker do to exploit this issue?

The CVSS vector indicates the attack can be delivered over a network without attacker privileges, but it requires user interaction. Successful exploitation can affect confidentiality, integrity, and availability.

2

How can I tell whether my Firefox ESR installation is affected?

Check the installed Firefox ESR version. The issue was fixed in Firefox ESR 115.45, so installations not updated to that fixed release should be remediated.

CVE-2026-124952: Use-after-free in the Audio/Video component

Affected Software

Remediation

Event History

Parent advisories

Peer vulnerabilities

Frequently Asked Questions

What must an attacker do to exploit this issue?

How can I tell whether my Firefox ESR installation is affected?

Company

Resources

Contact

Frequently Asked Questions

What must an attacker do to exploit this issue?

How can I tell whether my Firefox ESR installation is affected?